class_docstr: A `DecisionNode` encapsulates internal node in the tree
  Unlike a `LeafNode`, it contains very little actual logic beyond tying the tree together
code: def most_recent_split_condition(self) -> SplitCondition:
      return self.left_child.split.most_recent_split_condition()
  
imports: from typing import Union, Tuple
  from .data import Data
  from .split import Split, SplitCondition
label_desc: Use image node_id 3 for calling the DecisionNode obj's underlying member method code with example usage: obj.most_recent_split_condition() and returns: self